Formation of CLC-0 chloride channels from separated transmembrane and cytoplasmic domains.
CLC-0, a member of the CLC family of Cl(-)-conducting ion channels, consists of an N-terminal hydrophobic core and a C-terminal region that is thought to be cytoplasmic. This study provides evidence that the C-terminal region is a mechanistically relevant cytoplasmic domain of the CLC-0 ion channel. Both a point mutation and a 37-residue deletion in this region cause drastic alterations in voltage-dependent gating of CLC-0 current expressed in Xenopus oocytes. CLC-0 current is not observed when the entire C-terminal region is deleted, but functional channels are efficiently reconstituted by co-injection of separate cRNA constructs encoding the N-terminal transmembrane and the C-terminal cytoplasmic domains. Moreover, reconstitution of CLC-0 can be achieved by co-injection of cRNA encoding the transmembrane domain along with Escherichia coli-expressed C-terminal domain polypeptide.
Maduke
M
M
Howard Hughes Medical Institute, Department of Biochemistry, Brandeis University, Waltham, Massachusetts, USA.
Williams
C
C
Miller
C
C
D000818:Animals; D018118:Chloride Channels / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D003593:Cytoplasm / Q000378:metabolism*; D006041:Goats; D008565:Membrane Proteins / Q000378:metabolism*; D008845:Microinjections; D016297:Mutagenesis, Site-Directed; D009865:Oocytes / Q000502:physiology; D018408:Patch-Clamp Techniques; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D014981:Xenopus
D018118:Chloride Channels; D008565:Membrane Proteins